Indicating mechanism



June ll, 1940. J. w. ALLEN INDICA'IING MECHANISM Original Filed March 2, 1935 2 Sheets-Sheet l INVENToR. Jose/ob W. A//en BY Jun 11, `1944 J, w, ALLEN 2,204,463

` INDICATING MECHANISM original Filed March 2, `1935 2 sheets-sheet 2 INVENTOR.

Jose/0b M //e/f Patented June 11, 1940 mnloa'rmo MEcnANIsM Joseph W. Allen, East Orange, N. J., assignor to Eclipse Aviation Corporation, East Orange, N. J,. a corporation of New Jersey Application Maren '2, 1935, lseriali No. 9,101 Renewed May 17, 1938 This invention relates to indicators, and anl In the accompanying drawings the invention I is shown in aY form suitable for indicating the rate of tlow of a fluid iiowing through `a closed conduit,- but it is to be understood that the drawings are merely for the purpose of illustration and description and do"not constitute a definition of the limits of the invention, reference being had to the appended claims for such a deiintion of limits.

In the drawings:

Fig. 1 is a partly sectional representation of the measuring means employed in the preferred embodiment ofthe-invention, and the electrical energizing means forA said parts;

, Fig. 2 is a longitudinal sectional view of the impulse receiving,'or measuring unit;

Fig. 3 is a longitudinal sectional view of the impulse sending unit;

Fig. 4 is a face view of the light interrupting means 'along the line 4--4 of Fig. 3.

-Fig. 5 is a diagrammatic view of the relationship between the pawl and gear mechanism when the former is at its lowest position; and Fig. 6 is a diagrammatic view of the pawl and gear mechanism when the former is in a/position intermediate that of Fig. 1 on the one hand and that oi Fig. 5 on the other.

The primary impulse sending mechanism is shown as including alight source 8 which illu- Inmates an apertured and recessed disk 1 secured to the shaft ,3 of a relatively light impeller assembly 9 rotatable in a housing through which a fluid to be measured is adapted to flow, the housing having inlet and outlet passages I2 and I3, respectively, and bearings I4 and |5 in 'which the ends of the impeller shaft 3 are received.

The` disk 1 is of a diameter sumcient to bring the outer portions thereof into the path vof the light beam passing through tube I8 which oo nnects the lamp casing I3 with the casing 23 which encioses a photo-electric cell 2|. Due to the re cesses 22 cut in the disk 1 at regular intervals the light beam is intermittently enective to excite the cell 2|, the anode- 24 of which,is connected, through a manually controlled switch 25, to the positive terminal of a batteryA 25, while the cathode connects, through a lead 21, with the winding `.of a solenoid 2l constitutlngpart of the lli impulse receiving unit.

A which the pointer 34 may move before striking The impulse receiving unit also includes a glass covered`casing 3| having a stationary Aannular scale 32 including characters 33 and a pointer 34, the extent of movement of the pointer being proportional to the frequency of the impulses sent 5 into the solenoid 28 from theV cell 2|, and therelfore an indication of the rapidity of rotation of disk1, and hence of the rate of ilow through housing Each current impulse in solenoid 23 sets up a magnetic field acting upon core 35 to l0 raise it and thus impart movement to pointer 34 by the means now to be described.

The case 3| .has a shaft 43 held to the case by a nut 31. Spacers 38, 39, and 4|I are in turn held together by shaft 43. The spacers 33 and l5 39 have recesses adapted to'receive bevel gears 4| and 42, respectively, loosely mounted thereon, and coacting with an idler pinion 44, which pinion is mounted on shaft 45 held in positionby arm 41 fastened to housing 3|.

A pin 43 fastened to housing 3| supports one end of a lspiral spring 49. The other end of spiral spring 43 is fastened to pin 5|, which pin is riveted to gear 4 I. Pointer '34 is loosely tted to spacer 43. Spring 53 holds ppinter 34 against the shoulder on spacer 45. The pointer 34 being in balance will hold its position because of friction at the shoulder on spacer 40.

On gear 42 are located two pins 54, 55 between 30 either pin.

A pawl 51 is positioned to engage teeth'of gear 42. A spring 53 holds pawl 51 against the gear teeth when the pawl is moving upward but permits the pawl to move out of engagement with the teeth when descending. The pawl 51 is pivoted freely to a plunger 53 which receives a nut 5| at its lower end and passes through core 36 of the solenoid 28. Also within' the core 35V is a spring 53 acting upon the plunger 59 to cause it tomove with the core 36, the latter being supported in position by nut 5|, and normally'held against said nut by the action of a second'spring 54 which abuts the stationary pole piece 55 formed integrar with the housing 61.

The moving system having beenset in motion continues `in` mation until energy is stored ln spring 43, whereupon spring 45 moves the gears inthe reverse directions.

Spring 54 retracts pawl 51 as soon as the circuit 5o is interruptedallowing. pawl 51^to disengage the gear teeth.

It will be seen therefore that due to energy stored inspring 43 the movement oi gears 4| and 42 will be a function oi' the `kinetic energy of the u gears and the tension of spring 4B. If we now operate solenoid 28 at a given frequency the gears will be moved around until they move forward ythrough a short distance and then back a short distance so that the pointer 34 is stationary. the movement of the gears being too small to allow pins 54. to produce any further movement of the pointer.

At a greater frequency the gears are moved around further until another xed condition is reached.

The action of the gear moving means may best be understood by a study of Figs. 5 and 6. Referring rst to Fig. 5 the pawl 51 as shown in full lines therein, is in the non-engaging position corresponding to the lowest point of the stroke, while the dash lines indicate two higher points in the stroke. Fig. 6 shows the action when the rate of iiow is high enough to produce a high frequency action of the pawl, tending to shorten its stroke. Of course, before such high frequency is obtained the pointer 34 has moved around the dial to the position corresponding to full tensioning of the spring 49. W'hen this condition of maximum flow has been obtained, there will be. no further ad- Vance, for thereafter when gear 42 is released by pawl 51, it will be driven backward, by tensioned spring 49, the one-tooth advancement that had' just previously been imparted thereto, with no resultant advancement produced by the impulse energization of magnet 2l. This however is only true after the spring has been rather completely wound up; it is not true during the early stage of rotation of the pointer 34, for in the early stage the spring 49 is not tensioned sufliciently to equal the force of the repeated thrusts of pawl 51 as it moves at relatively rapid frequency. Hence pawl 51 is more effective to turn the gear 42-during this early stagewhile spring 49 is relatively ineffective as an opposing force. Gradually the preponderance of power vanishes, and a condition. of balanced forces results.

The foregoing covers two conditions. Now there is a third conditionthe condition of stoppage of flow.

When stoppage of ow occurs, the rate of energization of magnet 28 falls off and it soon stops altogether. When it stops the pawl is held in its lowest (non-engaged) position (by spring 64)..

Spring 48 is now unopposed by the pawl, and is free to spin the gear 42 all the way back to the zero positionbut only because pawl 81 is now dead. So long as pawl 51 remained active, no such complete return could be efl'ected.

Because of the use ofthe two interconnected gears 4|, 42 the inertia of each gear balances any 'tendency in the other gear to move with respect to the housing Il. As assembled the movement of one gear is in one direction while that of the other is in the opposite direction.

The invention is susceptible of various changes in its form, proportions and minor details of construction and the right is herein reserved to make such changes' as properly fall within the scope of the appended claims.

What is claimed is:

1. In combination with a series of characters, an index element movable along said series of characters, reciprocable variable stroke means for driving said index element forward, and means for imparting energizing impulses to said reciprocable means; the stroke of said reciprocable means being shortened as the energizing impulses become more frequent.

2. In combination with a series of characters. an index element movable along said series of characters, reciprocable variable stroke means for driving said index element forward, means for imparting energizing impulses to said reciprocable means; the stroke of said reciprocable means being shortened as the energizing impulses become more frequent; and means urging said index element backward in opposition to the force of said reciprocable variable stroke means.

3. In combination with a series of characters, an index element movable along said series of characters, reciprocable variable stroke means for driving said index element forward, means for imparting energizing impulses to said reciprocable means; the stroke of said reciprocable means being shortened as the energizing lmpuises become more frequent; means urging said index element backward in opposition to the force of said reciprocablesvariable stroke means, and means for holding said index element stationary after movement of said index element in either direction from one position to a new position.

JOSEPH W. ALLEN. 

